Biodiversity Research Cluster, Department of Biology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok, 10400, Thailand.
Center of Excellence for Vectors and Vector-Borne Diseases, Faculty of Science, Mahidol University at Salaya, Phutthamonthon 4 Road, Nakhon Pathom, 73170, Thailand.
Trop Biomed. 2022 Jun 1;39(2):191-196. doi: 10.47665/tb.39.2.009.
Birds are known to be the most mobile hosts and are therefore considered to be hosts with potential to contribute to the long-distance spread and transmission of tick-borne pathogens. In the present study, ticks were collected from a hornbill nest at Chaiyaphum Province, Thailand. They were screened for the presence of Coxiella bacteria using conventional PCR. The evolutionary relationships of positive Coxiella-like bacteria (CLB) were analysed based on the gene sequences of 16S rRNA, groEL and rpoB. Among all 22 tested ticks, CLB infections were found in 2 Haemaphysalis wellingtoni individuals. In a phylogenetic analysis, the Coxiella 16S rRNA gene detected in this study formed a separate clade from sequences found in ticks of the same genus. In contrast, the phylogenetic relationships based on groEL and rpoB revealed that these two genes from H. wellingtoni ticks grouped with CLB from the same tick genus (Haemaphysalis). This study is the first to report the presence of CLB in H. wellingtoni ticks associated with the Great Hornbill, Buceros bicornis in Thailand. Three genes of CLB studied herein were grouped separately with Coxiella burnetii (pathogenic strain). The effects of CLB in the ticks and Buceros bicornis require further investigation.
鸟类是已知最具移动性的宿主，因此被认为是具有潜在能力可促成蜱传病原体远距离传播和传播的宿主。在本研究中，从泰国猜也蓬府的犀鸟巢中收集了蜱虫。使用常规 PCR 筛选了这些蜱虫是否存在柯克斯氏体细菌。基于 16S rRNA、groEL 和 rpoB 基因序列分析了阳性柯克斯氏体样细菌 (CLB) 的进化关系。在所有测试的 22 只蜱虫中，在 2 只革蜱中发现了 CLB 感染。在系统发育分析中，本研究中检测到的柯克斯氏体 16S rRNA 基因与同属蜱虫中的序列形成了一个单独的分支。相比之下，基于 groEL 和 rpoB 的系统发育关系表明，这两种来自革蜱的基因与来自同一蜱属（Haemaphysalis）的 CLB 聚在一起。本研究首次报道了在与泰国大犀鸟（Buceros bicornis）相关的革蜱中存在 CLB。本研究中研究的 CLB 的三个基因与柯克斯氏体伯氏立克次体（致病株）分别聚在一起。蜱虫和大犀鸟中 CLB 的作用需要进一步研究。
